This invention relates to electrophotography. It is now well known in the art to make a copy of a document by forming a latent electrostatic image of the document on an electrophotographic member, toning the latent image to make it visible and then transferring the toned image to a sheet of carrier material such as paper.
The invention herein revolves around a type of electrophotographic film that is capable of being imaged with quality and gray scale as good as, if not better than, that achieved by photographic film and with resolution that is better than that achieved by photographic film. The film includes an inorganic coating of microcrystalline material that is bonded onto a conductive substrate. In a preferred embodiment the inorganic coating comprises a layer of radio frequency sputtered cadmium sulfide that is from about 2,000 Angstroms to about 2 microns thick and the conductive substrate comprises a layer of about 300 to 500 Angstroms thick of indium tin oxide which in turn is disposed on a sheet of stable polyester plastic about 5 mils thick. The film is described in U.S. Pat. No. 4,025,339 issued May 24, 1977.